feat: implement ratio lender (#51)

* feat: implement ratio lender

* feat: tests for ratio lender

.gas-snapshot

@@ -1,54 +1,68 @@
-TestAstariaV1Loan:testNewLoanERC721CollateralDefaultTermsRecallAuctionFailLenderClaim() (gas: 569882)
-TestAstariaV1Loan:testNewLoanERC721CollateralDefaultTermsRecallBase() (gas: 910054)
-TestAstariaV1Loan:testNewLoanERC721CollateralDefaultTermsRecallLenderClaimRandomFulfiller() (gas: 567197)
-TestAstariaV1Loan:testNewLoanERC721CollateralRecallNotBlockedBorrower() (gas: 473813)
-TestAstariaV1Loan:testNewLoanERC721CollateralRecallNotBlockedLender() (gas: 473538)
-TestAstariaV1Loan:testNewLoanERC721CollateralRecallerNotBorrowerOrLender() (gas: 446127)
-TestAstariaV1Pricing:testGetPaymentConsiderationIncrementation() (gas: 57195)
-TestAstariaV1Pricing:testGetRefinanceConsiderationAsBorrowerZeroRate() (gas: 60433)
-TestAstariaV1Pricing:testGetRefinanceConsiderationInsufficientRefinance() (gas: 95727)
-TestAstariaV1Pricing:testGetRefinanceConsiderationInvalidRefinance() (gas: 59300)
-TestAstariaV1Pricing:testGetRefinanceConsiderationValidEqualRate() (gas: 97989)
-TestAstariaV1Pricing:testGetRefinanceConsiderationValidHigherRate() (gas: 108970)
-TestAstariaV1Pricing:testGetRefinanceConsiderationValidLowerRate() (gas: 104617)
-TestAstariaV1Pricing:testGetRefinanceConsiderationZeroRate() (gas: 64686)
-TestAstariaV1Pricing:testGetRefinanceNewDecimalMismatch() (gas: 64618)
-TestAstariaV1Pricing:testV1PricingValidateInvalid() (gas: 56870)
-TestAstariaV1Pricing:testV1PricingValidateValid() (gas: 57388)
-TestAstariaV1Settlement:testGetSettlementConsideration() (gas: 440480)
-TestAstariaV1Settlement:testV1SettlementHandlerValidate() (gas: 436565)
-TestAstariaV1Settlement:testV1SettlementValidateInvalid() (gas: 51055)
-TestAstariaV1Settlement:testV1SettlementValidateValid() (gas: 50398)
-TestAstariaV1Status:testCannotRecallTwice() (gas: 530871)
-TestAstariaV1Status:testInvalidRecallLoanDoesNotExist() (gas: 497581)
-TestAstariaV1Status:testIsActive() (gas: 446151)
-TestAstariaV1Status:testIsRecalledInsideWindow() (gas: 541272)
-TestAstariaV1Status:testIsRecalledOutsideWindow() (gas: 538810)
-TestAstariaV1Status:testRecallAndRefinanceInsideWindow() (gas: 683957)
-TestAstariaV1Status:testRecallAndRefinanceWithLenderCaveat() (gas: 742794)
-TestAstariaV1Status:testRecallPauseable() (gas: 19669)
-TestAstariaV1Status:testRecallRateActiveRecall() (gas: 527199)
-TestAstariaV1Status:testRecallRateEmptyRecall() (gas: 446889)
-TestAstariaV1Status:testV1StatusValidateInValid() (gas: 58479)
-TestAstariaV1Status:testV1StatusValidateValid() (gas: 51916)
-TestCompoundInterest:testDecimalsTooHigh() (gas: 3318)
-TestCompoundInterest:testInterestAccrual() (gas: 52624)
-TestCompoundInterest:testMaxAmountDecimals() (gas: 7891)
-TestCompoundInterest:testRateExceedsMaxRecallRate() (gas: 3297)
+TestAstariaV1Loan:testNewLoanERC721CollateralDefaultTermsRecallAuctionFailLenderClaim() (gas: 569913)
+TestAstariaV1Loan:testNewLoanERC721CollateralDefaultTermsRecallBase() (gas: 910085)
+TestAstariaV1Loan:testNewLoanERC721CollateralDefaultTermsRecallLenderClaimRandomFulfiller() (gas: 567097)
+TestAstariaV1Loan:testNewLoanERC721CollateralRecallNotBlockedBorrower() (gas: 473733)
+TestAstariaV1Loan:testNewLoanERC721CollateralRecallNotBlockedLender() (gas: 473569)
+TestAstariaV1Loan:testNewLoanERC721CollateralRecallerNotBorrowerOrLender() (gas: 446158)
+TestAstariaV1Pricing:testGetPaymentConsiderationIncrementation() (gas: 57204)
+TestAstariaV1Pricing:testGetRefinanceConsiderationAsBorrowerZeroRate() (gas: 60464)
+TestAstariaV1Pricing:testGetRefinanceConsiderationInsufficientRefinance() (gas: 95736)
+TestAstariaV1Pricing:testGetRefinanceConsiderationInvalidRefinance() (gas: 59309)
+TestAstariaV1Pricing:testGetRefinanceConsiderationValidEqualRate() (gas: 97998)
+TestAstariaV1Pricing:testGetRefinanceConsiderationValidHigherRate() (gas: 109001)
+TestAstariaV1Pricing:testGetRefinanceConsiderationValidLowerRate() (gas: 104626)
+TestAstariaV1Pricing:testGetRefinanceConsiderationZeroRate() (gas: 64695)
+TestAstariaV1Pricing:testGetRefinanceNewDecimalMismatch() (gas: 64649)
+TestAstariaV1Pricing:testV1PricingValidateInvalid() (gas: 56901)
+TestAstariaV1Pricing:testV1PricingValidateValid() (gas: 57419)
+TestAstariaV1Settlement:testGetSettlementConsideration() (gas: 440400)
+TestAstariaV1Settlement:testV1SettlementHandlerValidate() (gas: 436596)
+TestAstariaV1Settlement:testV1SettlementValidateInvalid() (gas: 51064)
+TestAstariaV1Settlement:testV1SettlementValidateValid() (gas: 50429)
+TestAstariaV1Status:testCannotRecallTwice() (gas: 530858)
+TestAstariaV1Status:testInvalidRecallLoanDoesNotExist() (gas: 497612)
+TestAstariaV1Status:testIsActive() (gas: 446160)
+TestAstariaV1Status:testIsRecalledInsideWindow() (gas: 541303)
+TestAstariaV1Status:testIsRecalledOutsideWindow() (gas: 538841)
+TestAstariaV1Status:testRecallAndRefinanceInsideWindow() (gas: 683988)
+TestAstariaV1Status:testRecallAndRefinanceWithLenderCaveat() (gas: 742715)
+TestAstariaV1Status:testRecallPauseable() (gas: 19691)
+TestAstariaV1Status:testRecallRateActiveRecall() (gas: 527208)
+TestAstariaV1Status:testRecallRateEmptyRecall() (gas: 446920)
+TestAstariaV1Status:testV1StatusValidateInValid() (gas: 58510)
+TestAstariaV1Status:testV1StatusValidateValid() (gas: 51925)
+TestCompoundInterest:testDecimalsTooHigh() (gas: 3340)
+TestCompoundInterest:testInterestAccrual() (gas: 52646)
+TestCompoundInterest:testMaxAmountDecimals() (gas: 7913)
+TestCompoundInterest:testRateExceedsMaxRecallRate() (gas: 3319)
 TestCompoundInterest:testRateTooLowZero() (gas: 3413)
-TestV1BorrowerEnforcer:testFuzzRateMethods((uint256,uint256,uint256),uint256) (runs: 10000, μ: 1223, ~: 1223)
-TestV1BorrowerEnforcer:testRevertLocateCurrentRateAndAmount() (gas: 50278)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerCollateralAmountOOB() (gas: 112121)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerDebtAmountOOB() (gas: 99409)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerDebtBundlesNotSupported() (gas: 57321)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerEnd() (gas: 106805)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerHalfway() (gas: 101968)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerRateGTCurrent() (gas: 81834)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerRateLTCurrent() (gas: 89323)
-TestV1BorrowerEnforcer:testV1BorrowerEnforcerStart() (gas: 86476)
-TestV1LenderEnforcer:testV1LenderEnforcerAdditionalTransfers() (gas: 105167)
-TestV1LenderEnforcer:testV1LenderEnforcerAmount() (gas: 173982)
-TestV1LenderEnforcer:testV1LenderEnforcerDebtBundlesNotSupported() (gas: 63352)
-TestV1LenderEnforcer:testV1LenderEnforcerMatchIdentifier() (gas: 109746)
-TestV1LenderEnforcer:testV1LenderEnforcerMinDebtExceedsMax() (gas: 77387)
-TestV1LenderEnforcer:testV1LenderEnforcerRate() (gas: 102337)
+TestV1BorrowerEnforcer:testFuzzRateMethods((uint256,uint256,uint256),uint256) (runs: 10000, μ: 1245, ~: 1245)
+TestV1BorrowerEnforcer:testRevertLocateCurrentRateAndAmount() (gas: 50309)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerCollateralAmountOOB() (gas: 112152)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerDebtAmountOOB() (gas: 99418)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerDebtBundlesNotSupported() (gas: 57330)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerEnd() (gas: 106836)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerHalfway() (gas: 101999)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerRateGTCurrent() (gas: 81865)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerRateLTCurrent() (gas: 89310)
+TestV1BorrowerEnforcer:testV1BorrowerEnforcerStart() (gas: 86485)
+TestV1LenderEnforcer:testV1LenderEnforcerAdditionalTransfers() (gas: 105176)
+TestV1LenderEnforcer:testV1LenderEnforcerAmount() (gas: 173991)
+TestV1LenderEnforcer:testV1LenderEnforcerDebtBundlesNotSupported() (gas: 63361)
+TestV1LenderEnforcer:testV1LenderEnforcerMatchIdentifier() (gas: 109755)
+TestV1LenderEnforcer:testV1LenderEnforcerMinDebtExceedsMax() (gas: 77418)
+TestV1LenderEnforcer:testV1LenderEnforcerRate() (gas: 102346)
+TestV1RatioLenderEnforcer:testV1LenderEnforcerCopyBorrower() (gas: 82012)
+TestV1RatioLenderEnforcer:testV1LenderEnforcerCopyCollateralAmount() (gas: 81517)
+TestV1RatioLenderEnforcer:testV1LenderEnforcerCopyDebtAmount() (gas: 81325)
+TestV1RatioLenderEnforcer:testV1LenderEnforcerCopyOriginator() (gas: 84119)
+TestV1RatioLenderEnforcer:testV1RatioLenderCollateralBundle() (gas: 72008)
+TestV1RatioLenderEnforcer:testV1RatioLenderDebtAmountExceedsDebtMax() (gas: 79937)
+TestV1RatioLenderEnforcer:testV1RatioLenderDebtBundle() (gas: 71732)
+TestV1RatioLenderEnforcer:testV1RatioLenderDefault() (gas: 83916)
+TestV1RatioLenderEnforcer:testV1RatioLenderEnforcerAdditionalTransfers() (gas: 116076)
+TestV1RatioLenderEnforcer:testV1RatioLenderEnforcerMatchIdentifier() (gas: 112205)
+TestV1RatioLenderEnforcer:testV1RatioLenderEnforcerRate() (gas: 104962)
+TestV1RatioLenderEnforcer:testV1RatioLenderLoanRateLessThanCaveatRate() (gas: 79672)
+TestV1RatioLenderEnforcer:testV1RatioLenderMaxDebtOrCollateralToDebtRatioZero() (gas: 79502)
+TestV1RatioLenderEnforcer:testV1RatioLenderMinCollateralAmount() (gas: 105956)

src/enforcers/AstariaV1RatioLenderEnforcer.sol

@@ -0,0 +1,144 @@
+//  SPDX-License-Identifier: Apache-2.0
+//   █████╗ ███████╗████████╗ █████╗ ██████╗ ██╗ █████╗     ██╗   ██╗ ██╗
+//  ██╔══██╗██╔════╝╚══██╔══╝██╔══██╗██╔══██╗██║██╔══██╗    ██║   ██║███║
+//  ███████║███████╗   ██║   ███████║██████╔╝██║███████║    ██║   ██║╚██║
+//  ██╔══██║╚════██║   ██║   ██╔══██║██╔══██╗██║██╔══██║    ╚██╗ ██╔╝ ██║
+//  ██║  ██║███████║   ██║   ██║  ██║██║  ██║██║██║  ██║     ╚████╔╝  ██║
+//  ╚═╝  ╚═╝╚══════╝   ╚═╝   ╚═╝  ╚═╝╚═╝  ╚═╝╚═╝╚═╝  ╚═╝      ╚═══╝   ╚═╝
+//
+//  Astaria v1 Lending
+//  Built on Starport https://github.com/astariaXYZ/starport
+//  Designed with love by Astaria Labs, Inc
+
+pragma solidity ^0.8.17;
+
+import {Starport} from "starport-core/Starport.sol";
+import {CaveatEnforcer} from "starport-core/enforcers/CaveatEnforcer.sol";
+import {BasePricing} from "v1-core/pricing/BasePricing.sol";
+import {AdditionalTransfer} from "starport-core/lib/StarportLib.sol";
+import {AstariaV1Lib} from "v1-core/lib/AstariaV1Lib.sol";
+import {FixedPointMathLib} from "solady/src/utils/FixedPointMathLib.sol";
+
+contract AstariaV1RatioLenderEnforcer is CaveatEnforcer {
+    using FixedPointMathLib for uint256;
+
+    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
+    /*                       CUSTOM ERRORS                        */
+    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
+
+    error InvalidLoanTerms();
+    error InvalidAdditionalTransfer();
+    error LoanRateLessThanCaveatRate();
+    error DebtBundlesNotSupported();
+    error CollateralBundlesNotSupported();
+    error DebtAmountExceedsDebtMax(uint256 maxDebt, uint256 debtAmount);
+    error BelowMinCollateralAmount();
+    error MaxDebtOrCollateralToDebtRatioZero();
+
+    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
+    /*                          STRUCTS                           */
+    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
+
+    struct Details {
+        bool matchIdentifier;
+        uint256 minCollateralAmount;
+        uint256 collateralToDebtRatio; // WAD
+        Starport.Loan loan;
+    }
+
+    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
+    /*                     PUBLIC FUNCTIONS                       */
+    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
+
+    /// @notice Validates a loan against a caveat, w/ a minCollateralAmount, collateralToDebtRatio, and a matchIdentifier
+    /// @dev collateralToDebtRatio is a 1e18 value allowing a ratio conversion from collateral to debt, 1e18 was used to allow flexibility on the collateral units lower bound
+    /// @dev Collateral bundle support is not implemented, and will revert
+    /// @dev Debt bundle support is not implemented, and will revert
+    /// @dev matchIdentifier = false will allow the loan to have a different identifier than the caveat
+    /// @dev Only viable for use w/ AstariaV1Pricing and AstariaV1Status modules
+    function validate(
+        AdditionalTransfer[] calldata additionalTransfers,
+        Starport.Loan calldata loan,
+        bytes calldata caveatData
+    ) public view virtual override returns (bytes4 selector) {
+        if (loan.debt.length > 1) {
+            revert DebtBundlesNotSupported();
+        }
+
+        if (loan.collateral.length > 1) {
+            revert CollateralBundlesNotSupported();
+        }
+
+        Starport.Terms calldata loanTerms = loan.terms;
+        uint256 loanRate = abi.decode(loanTerms.pricingData, (BasePricing.Details)).rate;
+        uint256 debtAmount = loan.debt[0].amount;
+        AstariaV1Lib.validateCompoundInterest(
+            debtAmount,
+            loanRate,
+            AstariaV1Lib.getBaseRecallMax(loanTerms.statusData),
+            AstariaV1Lib.getBasePricingDecimals(loanTerms.pricingData)
+        );
+
+        Details memory details = abi.decode(caveatData, (Details));
+
+        uint256 collateralAmount = loan.collateral[0].amount;
+        if (details.minCollateralAmount > collateralAmount) {
+            revert BelowMinCollateralAmount();
+        }
+
+        uint256 maxDebt = collateralAmount.mulWad(details.collateralToDebtRatio);
+        if (debtAmount > maxDebt) {
+            revert DebtAmountExceedsDebtMax(maxDebt, debtAmount);
+        }
+
+        if (maxDebt == 0) {
+            revert MaxDebtOrCollateralToDebtRatioZero();
+        }
+
+        bytes memory caveatPricingData = details.loan.terms.pricingData;
+        if (loanRate < AstariaV1Lib.getBasePricingRate(caveatPricingData)) {
+            // Loan rate is less than the caveatDebt rate
+            revert LoanRateLessThanCaveatRate();
+        }
+
+        // Update the caveat loan rate
+        AstariaV1Lib.setBasePricingRate(caveatPricingData, loanRate);
+        Starport.Loan memory caveatLoan = details.loan;
+
+        if (!details.matchIdentifier) {
+            // Update the caveat loan identifier
+            caveatLoan.collateral[0].identifier = loan.collateral[0].identifier;
+        }
+
+        // Update the caveat debt and collateral amounts
+        caveatLoan.debt[0].amount = debtAmount;
+        caveatLoan.collateral[0].amount = collateralAmount;
+
+        // Hash and match w/ expected borrower and originator
+        _validate(additionalTransfers, loan, caveatLoan);
+        selector = CaveatEnforcer.validate.selector;
+    }
+
+    function _validate(
+        AdditionalTransfer[] calldata additionalTransfers,
+        Starport.Loan calldata loan,
+        Starport.Loan memory caveatLoan
+    ) internal pure {
+        caveatLoan.borrower = loan.borrower;
+        caveatLoan.originator = loan.originator;
+
+        if (keccak256(abi.encode(loan)) != keccak256(abi.encode(caveatLoan))) {
+            revert InvalidLoanTerms();
+        }
+
+        if (additionalTransfers.length > 0) {
+            uint256 i = 0;
+            for (; i < additionalTransfers.length;) {
+                if (additionalTransfers[i].from == loan.issuer) revert InvalidAdditionalTransfer();
+                unchecked {
+                    ++i;
+                }
+            }
+        }
+    }
+}

test/AstariaV1Test.sol

@@ -89,6 +89,30 @@ contract AstariaV1Test is StarportTest {
         return LenderEnforcer.Details({loan: refiLoan});
     }
 
+    function generateDefaultERC20LoanTerms() public view virtual returns (Starport.Loan memory) {
+        SpentItem[] memory newCollateral = new SpentItem[](1);
+        newCollateral[0] = SpentItem({itemType: ItemType.ERC20, token: address(erc20s[1]), identifier: 0, amount: 1e6});
+        SpentItem[] memory newDebt = new SpentItem[](1);
+        newDebt[0] = SpentItem({itemType: ItemType.ERC20, token: address(erc20s[0]), identifier: 0, amount: 1e18});
+        return Starport.Loan({
+            start: 0,
+            custodian: address(custodian),
+            borrower: borrower.addr,
+            issuer: lender.addr,
+            originator: address(0),
+            collateral: newCollateral,
+            debt: newDebt,
+            terms: Starport.Terms({
+                status: address(status),
+                settlement: address(settlement),
+                pricing: address(pricing),
+                pricingData: defaultPricingData,
+                settlementData: defaultSettlementData,
+                statusData: defaultStatusData
+            })
+        });
+    }
+
     // loan.borrower and signer.addr could be mismatched
     function _generateSignedCaveatBorrower(Starport.Loan memory loan, Account memory signer, bytes32 salt)
         public